If the sum of n terms of an A.P is n2 then its common difference is ______

common difference, d = 2(n-a)/(n-1)

Ans is 2 bcz AP is 1,3,5,7,9,11 here u can see that sum of first 2 terms is 4 thatis 2 sq. , sum of first 3 tems is 9 that is 3 sq. And so on

n/2 [ 2a +(n-1)d] = nOn solving ,2n - 2a = (n-1)d=> d = 2(n-a)/(n-1)Now, when n=1,d = 2(2-a)/(2-1) = 4 - 2aWhen n=2,d= 2(3-a)/(3-1) = 3-aWe know, that d is constant in an AP series. Hence, d = 4-2a = 3-a=> 2a- a= 4 - 3=> a = 1=> d = 3 - a = 3 - 1 = 2